Britain's four biggest banks are to award bonus payouts worth almost £5bn in the next few weeks even as the share prices of lenders are being hammered by deepening concerns about economic growth.

Sky News can reveal that boardroom pay committees at Barclays, HSBC, Lloyds Banking Group and Royal Bank of Scotland (RBS) are finalising plans to announce the bonus pots alongside their annual results.

The overall pot will be lower than the £5.2bn aggregate bonuses for the quartet of banks in 2014, insiders said on Friday.

The biggest payer will be HSBC, which sources said would award bonuses of just under £2.5bn.

HSBC, which is finalising a decision about whether to move its headquarters from London after a ten-month review, is by far the most profitable of the four banks, as well as the largest dividend-payer among them.

City sources said on Friday that its bonus pool, which is still in the process of being rubber-stamped by its remuneration committee, would be slightly lower than the $3.7bn (£2.56bn) handed out for 2014.

At Barclays, which has borne the brunt of shareholder anger over investment banking pay in recent years, bonuses will be down from £1.86bn to approximately £1.75bn, sources said.

Jes Staley, Barclays' new chief executive, is expected to announce a further reshaping of the bank on 1 March, when it will publish its full remuneration report.

Investors will be watching Mr Staley's announcement for the relative balance between payouts to staff and investors after previous controversy over the issue.

Lloyds and RBS, which are 9%- and 73%-owned by taxpayers respectively, will also cut their bonus pools from £369m and £421m in 2014.

Insiders said Lloyds planned to award in the region of £350m for its performance in 2015, which would include reductions to reflect a £120m fine from the City watchdog for its failure to handle payment protection insurance mis-selling complaints adequately.

RBS has drawn up plans to award less than £400m in bonuses - down from £421m - underlining the sharp reduction in the size of its investment bank and the fact that it will report its ninth consecutive annual loss on 26 February.

Both Lloyds and RBS will be bound by a renewal of a cap on cash bonuses of £2,000 per employee under an agreement with UK Financial Investments, the Treasury agency which manages taxpayers' stakes in the two banks.

The declining bonus pots will reflect a number of industry-wide factors, including regulators' requirement for banks to deduct part of the cost of regulatory misconduct and fines from variable pay awards.

Substantial job cuts at all four of the banks over the last year will explain part of the cut in bonuses, while the move by lenders to pay regular allowances to some senior staff because of a European Union cap on the ratio of fixed-to-variable pay has also influenced the scale of bonus awards.

As Sky News revealed last month, the major UK banks are also likely to set aside an aggregate of roughly £5bn in new provisions for PPI mis-selling as a deadline for compensation claims comes close to being imposed by the Financial Conduct Authority.

Barclays, HSBC, Lloyds and RBS all declined to comment.

Reacting to the news, shadow chancellor John McDonnell said: "If true, this will feel like a smack in the face to those consumers and taxpayers who bailed out the banks but have still not seen any rewards while bankers continue to be rewarded for failure.

"There's now a growing worry that it looks increasingly like the banks are returning to their old, bad habits from before the crisis and the Tories don't seem to have learnt a thing."